Machining plastic


Workpiece:Model Making Parts
MaterialPlastic, PVC, plexiglass
Type of application:2D milling, 3D milling
Used machine & accessories:High-Z router, plastic milling cutter
Used software:ConstruCAM 3D

CNC Machining of plastics


Thermoplastics, thermosetting plastics and elastomers

Besides wood and aluminum, machining plastic is another major field of CNC applications which includes the milling of soft plastics (thermoplastics) which are easy to shape under the effect of heat, solid plastics (thermosetting plastics) and cutting flexible plastics (elastomers) like rubber.

Fields of application

In sectors like model making, sign engraving or thermoforming plastic is machined day by day. The material is not only milled but also drilled, cut and engraved. Rubber, for example, cannot be milled, but only cut with a tangential knife. In this post, we deal with milling plastic giving you some useful tips on this subject.

Milling plastic by taking the example of POM

Tips on milling plastic

When milling plastic, some criteria have to be considered which are responsible for whether top results are achieved in the final product.


These points are important to consider:

1. Clamping free of tension

The clamping should be as free of tension as possible to obtain distortion-free results.

2. The cutting tool should be extremely sharp

The smoother a plastic is, the more difficult is the machining of the material. Also, polished flutes at the cutter help to evacuate the hot chips cleanly and reliably to prevent clogging of the flutes.

3. Cooling directly at the cutting tool

For most types of plastics, it is to required to cool the milling process directly on the router using a coolant. Often plain water is enough. The melting point of the material to be milled is lowered which also can prevent clogging on the cutter to prevent a final rupture.

4. Low rotational speed

You should choose the rotational speed of the cutting tool as low as possible when milling plastic to prevent increasing temperatures at the infeed point.

5. Deburring of the workpiece after milling

Plastic has to be deburred after milling because the chipping produces sharp edges which cause the risk of injury or the damage of power cables. For the sake of blunting the sharp edges, they are deburred with a special blade of a deburring tool.

Milling plastic with spray cooling

Milling plexiglass, polycarbonate and polystyrene

Every CNC router of our machine assortment has stable mechanics which allows not only to mill any plastic but also high precision. Our customers produce parts for making models, the advertising industry and the interior decoration of cars as well as instruments and lighted signs.

With our machines, you can mill all kinds of plexiglass and polycarbonate to a thickness of about 30mm. We even offer special polishing milling cutters which let the edges look like polished.

Our versatile machines engrave all plastics as well. You should use a working extraction with Plexiglas or at least get a permanent air cooling, due to the low melting point of about 80 ° C. Even better results are obtained in connection with a spray cooling.

lighted sign made of plexiglass

Conclusion on machining plastic

The most important thing is the right choice for the milling tool and a machine with stable mechanics! This milling tool must be sharp and of high quality! CNC-STEP routers mill all plastics with ease, high precision and accuracy to size. Whether you need to bring housing cutouts in finished plastic housing, must produce parts from POM or plexiglass – you get an appropriate machine and the proper accessories for machining plastic.

round milling of acrylic glass